/*相对于整个页面居中*/
.page-center{
    margin-top: 20%;
    text-align: center;
}

.mask_control{
    position: absolute;
    top: 0px;
    height: 100%;
    width:100%;
    text-align: center;
}
.mask_control img{
    top: 50%;
    transform: translateY(-50%);
    position: absolute;
}

.form_label {
    width: 40%;
    text-align: right;
}
.form-field {
    width: 40%;
    height: 100%;
}